Don't panic. Give them only selcon soaked food. I fought ich twice without any medication or temperature changes. Each time my fish made a full recovery and are now very healthy. Its better to boost the fish's natural immunity rather than medicating. It's better to be proacive at this point. Some fish will not recover naturally under good conditions and will go through this process all over.
What are your parameters, pH, nitrates, ammonia, nitrites, alkilinity, calcium etc and what kind of filtration do you use?
In my experience Ich always started with some stress causing factor. For example, if you are moving and rearranging your live rock frequently this can stress the fish.
Selcon is real cheap, soak Hikari Marine-S in Selcon for a few hours and drop the food very slowly with the back of a plastic spoon or fork. Turn off all the pump so it doesnt blow the selcon off the food. My fish love selcon soaked food. It also helps if you add a few drops of vitamin c after a few days to ease the recovery.
What we are trying to do here is help the fish develop Specific Imnnunity to the disease. Once the antibodies in the fish develop specific immune memory, the fish will naturally fight the pathogen, preventing re-infection.
vitamin C biosynthesis does not occur in fish due to the
lack of certain enzymes. This powerful antioxidant is helpful in boosting the fish's natural immune system especially when it's stressed.
Few things or lack there of that will stress the fish: crowding, handling, bad water quality, unusual temeperature, pollutants(contamination), well balanced diet with Omega-3 etc.
It will take you 7 days or more to fight Ich using this method(given that all your other parameters are good)
You can use garlic aswell. Some pictures of your fish, tank and more details about your water chemistry will help us see the problem better.
.Thanks!
